In a facsimile system, a document scanner converts the information printed on a document into a series of electrical signals which are transmitted to a receiving device whereat a copy of the original document is produced. The document to be scanned is placed on a transparent pane providing a document support surface. The document is scanned by a scanning mechanism which views selected, illuminated portions of the document through the pane. In such scanners, the document is generally illuminated by an elongated fluorescent light source. The light source is positioned adjacent a viewing aperature of the scanning mechanism. Occasionally, during routine maintenance of the scanner, the light source and viewing aperature require cleaning. Heretofore, cleaning of the scanning mechanism has been difficult since removal of the light source was usually necessary to obtain access to the aperature and surrounding areas. The bracket assembly disclosed provides a convenient mounting for a fluorescent light source which greatly facilitates bulb replacement and cleaning of the scanning mechanism.